Dental age estimation: Demirjian's versus the other methods in different populations. A literature review

Efficacy of the methods of age determination using artificial intelligence in panoramic radiographs - a systematic review

The aim of this systematic review is to analyze the literature to determine whether the methods of artificial intelligence are effective in determining age in panoramic radiographs. Searches without language and year limits were conducted in PubMed/Medline, Embase, Web of Science, and Scopus databases. Hand searches were also performed, and unpublished manuscripts were searched in specialized journals. Thirty-six articles were included in the analysis. Significant differences in terms of root mean square error and mean absolute error were found between manual methods and artificial intelligence techniques, favoring the use of artificial intelligence (p < 0.00001). Few articles compared deep learning methods with machine learning models or manual models. Although there are advantages of machine learning in data processing and deep learning in data collection and analysis, non-comparable data was a limitation of this study. More information is needed on the comparison of these techniques, with particular emphasis on time as a variable.

OPG-based dental age estimation using a data-technical exploration of deep learning techniques

Dental age estimation, a cornerstone in forensic age assessment, has been extensively tried and tested, yet manual methods are impeded by tedium and interobserver variability. Automated approaches using deep transfer learning encounter challenges like data scarcity, suboptimal training, and fine-tuning complexities, necessitating robust training methods. This study explores the impact of convolutional neural network hyperparameters, model complexity, training batch size, and sample quantity on age estimation. EfficientNet-B4, DenseNet-201, and MobileNet V3 models underwent cross-validation on a dataset of 3896 orthopantomograms (OPGs) with batch sizes escalating from 10 to 160 in a doubling progression, as well as random subsets of this training dataset. Results demonstrate the EfficientNet-B4 model, trained on the complete dataset with a batch size of 160, as the top performer with a mean absolute error of 0.562 years on the test set, notably surpassing the MAE of 1.01 at a batch size of 10. Increasing batch size consistently improved performance for EfficientNet-B4 and DenseNet-201, whereas MobileNet V3 performance peaked at batch size 40. Similar trends emerged in training with reduced sample sizes, though they were outperformed by the complete models. This underscores the critical role of hyperparameter optimization in adopting deep learning for age estimation from complete OPGs. The findings not only highlight the nuanced interplay of hyperparameters and performance but also underscore the potential for accurate age estimation models through optimization. This study contributes to advancing the application of deep learning in forensic age estimation, emphasizing the significance of tailored training methodologies for optimal outcomes.

Dental age estimation: A comparative study of convolutional neural network and Demirjian's method

The aim of this study is to compare a technique using Convolutional Neural Network (CNN) with the Demirjian's method for chronological age estimation of living individuals based on tooth age from panoramic radiographs. This research used 5898 panoramic X-ray images collected for diagnostic from pediatric patients aged 4-17 who sought treatment at Antalya Oral and Dental Health Hospital between 2015 and 2020. The Demirjian's method's grading was executed by researchers who possessed appropriate training and experience. In the CNN method, various CNN architectures including Alexnet, VGG16, ResNet152, DenseNet201, InceptionV3, Xception, NASNetLarge, InceptionResNetV2, and MobieNetV2 have been evaluated. Densenet201 exhibited the lowest MAE value of 0.73 years, emphasizing its superior accuracy in age estimation compared to other architectures. In most age categories, the predicted age closely matches the actual age. The most inconsistent results are observed at ages 12 and 13. The results highlight correspondence between the age predicted by CNN and the Demirjian's approach. In conclusion, the results show that the CNN method is adequate to be an alternative to the Demirjian's age estimation method. We suggest that convolutional neural network can effectively optimize the accuracy of age estimation and can be faster than traditional methods, eliminating the need for additional learning from experts.

Association between dental age and malocclusions: a systematic review

BACKGROUND

The evidence in the literature suggests that some skeletal or dental malocclusions are involved with dental development, resulting in advanced or delayed dental age (DA). The purpose of this systematic review was to investigate the association between DA and different types of malocclusions.

METHODS

The search was carried out on PubMed, Scopus, Web of Science, Virtual Health Library, and in the gray literature. Observational studies that evaluated the association between DA and sagittal, vertical, or transversal malocclusions were included. The quality assessment was performed using the Newcastle-Ottawa Scale (NOS). The data from primary studies were narratively synthesized. The certainty of evidence was evaluated using the GRADE approach. The study was conducted from August 2023 to October 2023.

RESULTS

One Thousand Nine Hundred Ninety-One records were identified in the initial search. Twenty (n = 20) studies were included. Most of the studies (n=15) presented a moderate quality according to NOS. Twelve studies evaluated the association between DA and sagittal discrepancies; eight studies evaluated vertical discrepancies, and only one study analyzed a transversal discrepancy. Demirjian's method for DA assessment was the most used among the studies. The primary studies observed that patients of both sexes presenting a vertical growth pattern and males with skeletal Class III malocclusion tend to have advanced DA. The study that investigated transversal malocclusion found that unilateral posterior cross-bite is associated with delayed DA. The certainty of evidence was very low for all outcomes evaluated.

CONCLUSION

DA may be associated with the type of malocclusion. It is suggested that DA can be used as an initial diagnostic tool in orthodontics. Future well-designed studies should be performed in order to investigate the association between DA and different types of malocclusions in more detail.

TRIAL REGISTRATION

This study was registered in the PROSPERO database (CRD42023454207).

Accelerating computer vision-based human identification through the integration of deep learning-based age estimation from 2 to 89 years

Computer Vision (CV)-based human identification using orthopantomograms (OPGs) has the potential to identify unknown deceased individuals by comparing postmortem OPGs with a comprehensive antemortem CV database. However, the growing size of the CV database leads to longer processing times. This study aims to develop a standardized and reliable Convolutional Neural Network (CNN) for age estimation using OPGs and integrate it into the CV-based human identification process. The CNN was trained on 50,000 OPGs, each labeled with ages ranging from 2 to 89 years. Testing included three postmortem OPGs, 10,779 antemortem OPGs, and an additional set of 70 OPGs within the context of CV-based human identification. Integrating the CNN for age estimation into CV-based human identification process resulted in a substantial reduction of up to 96% in processing time for a CV database containing 105,251 entries. Age estimation accuracy varied between postmortem and antemortem OPGs, with a mean absolute error (MAE) of 2.76 ± 2.67 years and 3.26 ± 3.06 years across all ages, as well as 3.69 ± 3.14 years for an additional 70 OPGs. In conclusion, the incorporation of a CNN for age estimation in the CV-based human identification process significantly reduces processing time while delivering reliable results.

Deep learning-based age estimation from chest CT scans

PURPOSE

Medical imaging can be used to estimate a patient's biological age, which may provide complementary information to clinicians compared to chronological age. In this study, we aimed to develop a method to estimate a patient's age based on their chest CT scan. Additionally, we investigated whether chest CT estimated age is a more accurate predictor of lung cancer risk compared to chronological age.

METHODS

To develop our age prediction model, we utilized composite CT images and Inception-ResNet-v2. The model was trained, validated, and tested on 13,824 chest CT scans from the National Lung Screening Trial, with 91% for training, 5% for validation, and 4% for testing. Additionally, we independently tested the model on 1849 CT scans collected locally. To assess chest CT estimated age as a risk factor for lung cancer, we computed the relative lung cancer risk between two groups. Group 1 consisted of individuals assigned a CT age older than their chronological age, while Group 2 comprised those assigned a CT age younger than their chronological age.

RESULTS

Our analysis revealed a mean absolute error of 1.84 years and a Pearson's correlation coefficient of 0.97 for our local data when comparing chronological age with the estimated CT age. The model showed the most activation in the area associated with the lungs during age estimation. The relative risk for lung cancer was 1.82 (95% confidence interval, 1.65-2.02) for individuals assigned a CT age older than their chronological age compared to those assigned a CT age younger than their chronological age.

CONCLUSION

Findings suggest that chest CT age captures some aspects of biological aging and may be a more accurate predictor of lung cancer risk than chronological age. Future studies with larger and more diverse patients are required for the generalization of the interpretations.

Comparison of Demirjian's comprehensive chart with the London atlas of tooth development in children and adolescents: a pilot study

Dental age estimation has its application in various subdisciplines of medicine and dentistry. New methods of dental age (DA) estimation are emerging and it is important that we compare different methods to determine which one is more closely related to the chronological age. Demirjian's method is one of the most widely used techniques and has been tested in various ethnic populations globally. In 2016, another approach to DA estimation is the London atlas of human tooth development and eruption. No study has compared Demirjian's comprehensive chart and London atlas method in the Indian population. Hence, in the current study, we estimated DA using Demirjian's comprehensive chart and London atlas method for association with the known chronologic age in children and adolescent population. The study also attempted to determine if sexual dimorphism existed in DA estimated by the two methods. Estimation was performed for both methods on 100 orthopantomogram records (50 males and 50 females, aged 6-16 years) of orthodontic patients. The data were compared and analysed using paired t-tests. There was an overestimation of DA by Demirjian's comprehensive chart on an average of +1.3 years in males and +0.5 years in females, whereas using London atlas, it was +1.4 years in males and +0.5 years in females. The mean of underestimation was -0.6 years in males and -0.8 years in females using Demirjian's comprehensive chart, whereas it was -0.8 years in males and -0.5 years in females. A statistically significant difference (P < 0.0001) was found when mean chronological age (11.6 ± 2.6) years of the participants was compared with DA estimated using either Demirjian's comprehensive chart (12.3 ± 2.8) years or London atlas (11.8 ± 2.9) years. The trends in this pilot study point towards more accuracy of London atlas over Demirjian's method when done using comprehensive chart for estimating DA. In summary, the results of the current pilot study indicates greater accuracy of London atlas method over Demirjian's comprehensive chart method for estimating DA in Indian population. This finding should be validated by conducting similar studies using larger sample, on diverse Indian ethnic populations, for applicability in pedodontic, orthodontic, and forensic domains.

Key points

No study has compared Demirjian's comprehensive chart and London atlas method in the Indian population.The dental age estimated by London method was closer to chronological age as compared to Demirjian's method in our study sample.Significant difference was found in chronological age and estimated age using London atlas method in both males and females.

Dental age assessment: scoring systems and models from the past until the present-how is it presented in the court?

OBJECTIVE

The aim of this study is to evaluate the accuracy of the methods from the past and present, such as Demirjian, Cameriere, and AlQahtani, as well as to determine the most reliable method for human age estimation under the request from the courts according to the effect size from each method in age estimation.

DESIGN

Four hundred eighty-three orthopantomographic images were selected from 318 patients from Centro Hospitalar Universitário Lisboa Norte aged between 6 and 15 years old. Several measurements of widths and lengths and classification of tooth development stages were performed, according to each age estimation method. The listing of patients and orthopantomographic images were consulted through SECTRA®. All data was entered and analysed using SPSS version 28. Observations' validity was verified through inter- and intraobserver validation.

RESULTS

The correlation coefficients between age and age estimates by the three methods on both sides were close to 90%. Regarding the estimation error correlation coefficient, Demirjian and AlQahtani values were low, whereas Cameriere's was significantly negative; i.e., underestimation increases as age increases. Between left and right, any significant difference in age estimation in AlQahtani and Cameriere methods was not observed, but there were great variability and large effect for the Demirjian method. Comparing females and males, the statistical analysis showed no significant differences and quite small effects in the precision of the estimates for any of the methods. Finally, although significant differences were detected when comparing estimated values and age, small effects were revealed except for the Demirjian method which attained a medium effect and, therefore, less consistency of estimation.

CONCLUSIONS

Since it was not possible to determine the most reliable method for age estimation, a combined application of different age estimation methodologies is recommended to be use in the courts with relevant statistical data such as effect size.

Radiographic dental age estimation applying and comparing Demirjian's seven (1973) and four (1976) teeth methods

To apply Demirjian's seven (1973, D7) and four (1976, D4) teeth methods in a sample of Brazilian children and compare their performances for age estimation. Panoramic radiographs of 1200 children (600 females and 600 males) were collected from Southeast Brazil. The children were equally distributed (n = 60 females and 60 males) between age intervals of 1 year between 6 and 15.9 (mean age = 10.9; standard deviation [SD]: 2.9) years. D7 and D4 dental age estimation methods were applied by two observers and were compared based on their error rates (error = estimated age-chronological age). Both methods overestimated the chronological age (p < 0.0001). D7 led to overestimations of 0.71 (p < 0.0001) in females and 0.83 (p < 0.0001) in males, while the overestimations with D4 were 0.14 (p = 0.0067) and 0.73 (p < 0.0001) for females and males, respectively. The mean age estimated by D7 was 11.7 (SD: 3.1) years, while for D4, it was 11.3 (SD: 3.3) years. Intra- and interobserver agreement was ≥ 0.98. D4 optimized the performance of radiographic dental age estimation compared to D7. Improvements were reflected in the total sample and separately for female and male children from Southeast Brazil.

Cameriere's open apices methodology for dental age estimation in children: a scoping review from a Latin American perspective

Dental age estimation (DAE) is key to establishing an individual's identity, and this is relevant in minors. A widely used method for DAE in children is Cameriere's open apices (CAM). Despite its wide dissemination, there are no clear reports of its use in Latin American populations. A scoping review was conducted using a search strategy in the PubMed/MEDLINE database, Web of Science, and a complementary manual search. Only papers using CAM or its regression equation models for evaluating Latin American populations were included. Ten studies published between 2007 and 2020 responded to the search objective. Brazil was the country with the most studies using CAM (7/10), and the University of Macerata (Italy) was the most declared affiliation (6/10). Seven studies used the original CAM formula in populations from Brazil and Peru, while the European formula (EuCAM) was applied in Mexico, Colombia, and Brazil. Although the method underestimated the age values with acceptable error margins, the correction factor substantially improved the predictive power of the method. Some limitations of the method are highlighted. CAM and its variants can be useful for validation in Latin American settings, but attention to population structures and terminologies is suggested for future research.

Preliminary study on genetic factors related to Demirjian's tooth age estimation method based on genome-wide association analysis

The age determination of individuals, especially minors, is critical in forensic research. In forensic practice, dental age estimation is one of the most commonly used methods for determining age as teeth are easy to preserve and relatively resistant to environmental factors. Tooth development is affected and regulated by genetic factors; however, these are not incorporated into current commonly used tooth age inference methods, leading to unreliable results. Here, we established a Demirjian and a Cameriere tooth age estimation-based methods suitable for use in children in southern China. By using the difference between the inferred age and the actual age (MD) as the phenotype, we identified 65 and 49 SNPs related to tooth age estimation from 743,722 loci among 171 children in southern China through a genome-wide association analysis (p<0.0001). We also conducted a genome-wide association study on dental development stage (DD) using the Demirjian tooth age estimation method and screened two sets of SNP sites (52 and 26) based on whether age difference was considered. The gene function enrichment analysis of these SNPs found that they were related to bone development and mineralization. Although SNP sites screened based on MD seem to improve the accuracy of tooth age estimation, there is little correlation between these SNPs and an individual's Demirjian morphological stage. In conclusion, we found that individual genotypes can affect tooth age estimation, and based on different phenotypic analysis models, we have identified some novel SNP sites related to tooth age inference and Demirjian's tooth development stage. These studies provide a reference for subsequent phenotypic selection based on tooth age inference analysis, and the results could possibly be used in the future to make forensic age estimation more accurate.

How old are you? A systematic review investigating the relationship between age and mandibular third molar maturity

INTRODUCTION AND OBJECTIVE

Radiographic evaluation of the maturity of mandibular third molars is a common method used for age estimation of adolescents and young adults. The aim of this systematic review was to examine the scientific base for the relationship between a fully matured mandibular third molar based on Demirjian's method and chronological age, in order to assess whether an individual is above or below the age of 18 years.

METHODS

The literature search was conducted in six databases until February 2022 for studies reporting data evaluating the tooth maturity using Demirjian´s method (specifically stage H) within populations ranging from 8 to 30 years (chronological age). Two reviewers screened the titles and abstracts identified through the search strategy independently. All studies of potential relevance according to the inclusion criteria were obtained in full text, after which they were assessed for inclusion by two independent reviewers. Any disagreement was resolved by a discussion. Two reviewers independently evaluated the risk of bias using the assessment tool QUADAS-2 and extracted the data from the studies with low or moderate risk of bias. Logistic regression was used to estimate the relationship between chronological age and proportion of subjects with a fully matured mandibular third molar (Demirjian´s tooth stage H).

RESULTS

A total of 15 studies with low or moderate risk of bias were included in the review. The studies were conducted in 13 countries and the chronological age of the investigated participants ranged from 3 to 27 years and the number of participants ranged between 208 and 5,769. Ten of the studies presented the results as mean age per Demirjian´s tooth stage H, but only five studies showed the distribution of developmental stages according to validated age. The proportion of subjects with a mandibular tooth in Demirjian´s tooth stage H at 18 years ranged from 0% to 22% among males and 0 to 16% in females. Since the studies were too heterogenous to perform a meta-analysis or a meaningful narrative review, we decided to refrain from a GRADE assessment.

CONCLUSION

The identified literature does not provide scientific evidence for the relationship between Demirjian´s stage H of a mandibular third molar and chronologic age in order to assess if an individual is under or above the age of 18 years.

[Forensic medical diagnostics of age by the Cameriere method]

THE AIM OF THE STUDY

Was to conduct the comparative analysis of the age groups' separation accuracy (<18 years old; ≥18 years old) by orthopantomogram depending on the examination's side in Russian population sample. The number of orthopantomograms equal 600 (190 of male and 410 of female) aged from 14 to 23 were investigated. Index value of third molar (Im³) was calculated by the R. Cameriere method, in female and male, on the right and left sides. Index of third molar on the right and left sides shows a high correlation. In the male sample the result specificity was 0.97 on the left and 1.0 on the right, the sensitivity was 0.96 on the left and 0.94 on the right. In the female sample the values were as follows: the specificity was 0.96 on the left and 0.98 on the right, the sensitivity was 0.92 on the left and 0.94 on the right. The results showed the possibility of Im³ (0.08) use to determine the target age group for Russian citizens of both sexes regardless of examination side.

Validity of age estimation methods and reproducibility of bone/dental maturity indices for chronological age estimation: a systematic review and meta-analysis of validation studies

Several approaches have been developed to estimate age, an important aspect of forensics and orthodontics, using different measures and radiological examinations. Here, through meta-analysis, we determined the validity of age estimation methods and reproducibility of bone/dental maturity indices used for age estimation. The PubMed and Google Scholar databases were searched to December 31, 2021 for human cross-sectional studies meeting pre-defined PICOS criteria that simultaneously assessed the reproducibility and validity. Meta-estimates of validity (mean error: estimated age-chronological age) and intra- and inter-observer reproducibility (Cohen’s kappa, intraclass correlation coefficient) and their predictive intervals (PI) were calculated using mixed-effect models when heterogeneity was high (I² > 50%). The literature search identified 433 studies, and 23 met the inclusion criteria. The mean error meta-estimate (mixed effects model) was 0.08 years (95% CI − 0.12; 0.29) in males and 0.09 (95% CI − 0.12; 0.30) in females. The PI of each method spanned zero; of nine reported estimation methods, Cameriere’s had the smallest (− 0.82; 0.47) and Haavikko’s the largest (− 7.24; 4.57) PI. The reproducibility meta-estimate (fixed effects model) was 0.98 (95% CI 0.97; 1.00) for intra- and 0.99 (95% CI 0.98; 1.00) for inter-observer agreement. All methods were valid but with different levels of precision. The intra- and inter-observer reproducibility was high and homogeneous across studies.

Forensic odontology and dental age estimation research: a scoping review a decade after the NAS report on strengthening forensic science

Dental age estimation (DAE) is one of the most reliable and useful scientific methods employed by forensic odontology (FO) for human identification. In 2009, the US National Academy of Sciences (NAS) report highlighted the need to deepen research in many disciplines, among which FO received strong criticism for specific expertise. The aim of this review is to provide a comprehensive overview in order to systematically map the latest original research done in FO, as well as identify DAE within this field. A systematic search was performed from 2014 to 2019. In total, 644 studies were identified for qualitative analysis: DAE was the most studied topic (41.30%). Asia was the most productive continent with 58.27% of the global production on DAE; India was the most productive Asian country, with 32.33% and 55.48% of global and Asian production, respectively. The University of Macerata (Italy), KU Leuven (Belgium), University of Split (Croatia), and University of São Paulo (Brazil) led DAE research. Authors from leading countries on DAE research demonstrated great individual productivity, which is evidence of their scientific efforts, but also possible risks if the continuity of this line of research depends on them. Although FO has significantly focused its research on DAE, the absence of publications on controversial topics but necessary for research according to the NAS report shows the possible lack of interest of authors or journals to address them.

A large sample-sized study on dental development of children treated at the Central Dental Clinic (OCEx) of the Brazilian Army

OBJECTIVES

To test and compare the performance of two radiographic methods for dental age estimation on a large sample of Brazilian boys and girls.

MATERIAL AND METHODS

The sample consisted of 1.990 panoramic radiographs of Brazilian children (age: 3-15.9 years) equally balanced based on sex. The sample was distributed into ten age categories, each with up to 200 children. Age estimation was performed with Willems' (2001) and Demirjian's (1973) methods. Estimated (EA) and chronological (CA) ages were compared. The performances of the methods were quantified based on sex and age category.

RESULTS

The overall differences between CA and EA for Willems' method in boys and girls were 0.06 and - 0.02, respectively. For Demirjian's method, the differences were 0.60 and 0.74, respectively. The overestimations of Demirjian's method were statistically significant (p < 0.001). Willems' method reached the best outcomes among children between 3 and 12 years, while Demirjian's best performances were between the ages of 7 and 10 years.

CONCLUSION

Willems' method led to differences between CA and AE that were acceptable for clinical and forensic practice.

CLINICAL RELEVANCE

Age estimation may guide clinical decisions based on treatment timing. Validating international tools is necessary to promote evidence-based practice and country-specific application. This study overcame the limitations of previous research to provide a more realistic perspective of the performance of age estimation methods in Brazilian children. Willems' method had a superior performance compared to Demirjian's method and led to outcomes that were better than most studies with the Brazilian population.

Age Assessment in Children and Adolescents by Measuring the Open Apices in Teeth: A New Sardinian Formula

Age estimation in children is fundamental in both clinical and forensic fields. The aim of this study was to evaluate the accuracy of the Cameriere’s European and Italian formulae for age estimation in Sardinian children and adolescents, a genetically isolated population. A sample of 202 orthopantomograms of healthy Sardinian children and adolescents (100 females and 102 males) aged between 6 and 17 years was retrospectively evaluated. The seven left mandibular teeth were assessed with the Cameriere’s European and Italian formulae. The teeth with closed apex (N0) were counted and, in the teeth with open apex, the distance between the inner sides was calculated. All variables showed a significant and negative correlation with age except N0 and g. Sex (g), the variables s, N0, and the first-order interaction between them, contributed substantially to the age measurement (p < 0.001). Although the value of x5 had a low prediction level, it generated the following multiple linear regression formula, specific for the Sardinian sample: Age = 10.372 + 0.469 g + 0.810 N0 − 1.079 s − 0.398 s ∙ N0 − 0.326 × 5. Only the Sardinian and European formulae allowed to obtain an acceptable interclass agreement (both the lower and upper >0.7). The results showed that the European formula could be accurate for assessing age in this sample of children and adolescents.

A probability model for assessing age relative to the 18-year old threshold based on magnetic resonance imaging of the knee combined with radiography of third molars in the lower jaw

OBJECTIVE

This study aims to generate a statistical model based on magnetic resonance imaging of the knee and radiography of third molars in the lower jaw, for assessing age relative to the 18-year old threshold.

METHODS

In total, 58 studies correlating knee or tooth development to age were assessed, 5 studies for knee and 7 studies for tooth were included in the statistical model. The relation between the development of the anatomical site, based on a binary system, and age were estimated using logistic regression. Separate meta-populations for knee and tooth were generated from the individual based data for men and women. A weighted estimate of probabilities was made by combining the probability densities for knee and tooth. Margin of errors for males and females in different age groups and knee and tooth maturity were calculated within the larger framework of transition analysis using a logit model as a base. Evidentiary values for combinations of knee and tooth maturity were evaluated with likelihood ratios.

RESULTS

For males, the sensitivity for the method was calculated to 0.78 (probability of correctly classifying adults), the specificity 0.90 (probability of correctly classifying minors), the negative predictive value 0.80 (proportion identified minors are minors) and the positive predictive value 0.89 (proportion identified adults are adults) indicating a model better at identifying minors than adults. The point at which half the female population has reached closed knee lies before the 18-year threshold, adding the knee as an indicator lowers specificity and increases sensitivity. The sensitivity when using tooth as an indicator for females is 0.24 and specificity 0.97, signifying few minors misclassified as adults but also a low probability of identifying adults. The negative predictive value for women when using tooth as the sole indicator is 0.56 and positive predictive value 0.88. Probabilities were calculated for males and females assuming a uniform age distribution between 15 and 21years. The calculated margin of error of minors classified as adults in a population between 15 and 21 years with the model was 11% for males and 12% for females. Further, the evidentiary value as well as margin of error vary for different combinations of knee and tooth maturity.

CONCLUSION

The statistical model based on the combination of MRI knee and radiography of mandibular third molars is a valid method to assess age relative to the 18-year old threshold when applied on males and of limited value in females.